When observing a comet please try to forget how bright you think the comet
should be, what it was when you last viewed it, what other observers think
it is or what the ephemeris says it should be.

The equations for the light curves of comets that are currently visible
use only the raw observations and should give a reasonable prediction for
the current brightness. If the comet has not yet been observed or has
gone from view a correction for aperture is included, so that telescopic
observers should expect the comet to be fainter than given by the equation.
The correction is about 0.033 per centimetre. Values for the r parameter
given in square brackets [ ] are assumed. The form of the light curve is
either the standard m = H0 + 5 log d + K0 log r or the linear brightening
m = H0 + 5 log d + L0 abs(t - T + D0) where T is the date of perihelion,
t the present and D0 an offset, if L0 is +ve the comet brightens towards
perihelion and if D0 is +ve the comet is brightest prior to perihelion.

Full details of recently discovered objects will not appear until they are
available on the CBAT web pages. The actual accuracy of preliminary orbits is often
(nearly always) much worse than the published
accuracy implies. In part this is because
each orbital solution is treated as a mathematical construct and does not take account of observational
error. JPL does publish the errors, whereas the MPECs do not.

2013 A1 (Siding Spring)
An 18th magnitude comet was discovered at Siding Spring on January 3.54. Follow-up
observations led to pre-discovery observations from the Catalina Sky Survey made on
2012 December 8. It was discovered when still 7.2 au from the Sun, and does not
reach its 1.4 au perihelion until 2014 October. [MPEC 2013-A14, 2013 January 5] It
is a southern hemisphere
object and was at its brightest of around 9th magnitude in early September. It appears not to be a very
active object and is now fading.

The comet will pass very
close to Mars on 2014 October 19 at 18:26, missing by a nominal 0.00093 au. This is
based on observations over a 694 day arc. The orbit has an Earth Minimum Orbit Intersection
Distance (MOID) of 0.38 au. Despite the relatively low activity it might be -5 in
Martian skies, though would probably be fainter than this due to the delta effect.
Although NASA spacecraft imaged the comet during its close approach the images released so
far show nothing more than a fuzzy object.

2013 A2 (P/Scotti)
Jim Scotti discovered a 20th magnitude comet in Spacewatch images taken with the 0.9-m f/3 reflector
at Kitt Peak on January 6.29. The
preliminary orbit was based on a two day arc, yet gave values to five significant figures.
[MPEC 2013-A45, 2013 January 8] It has a period of 8 years and was at perihelion at
2.2 au in February. It approaches within 0.6 au of Jupiter, but these encounters have
made only minor changes to the orbit.
2013 A3 (277P/LINEAR)
Jim Scotti recovered 2005 YQ127 in Spacewatch II images taken with the 1.8-m f/2.7 reflector
at Kitt Peak on January 7.10. It has a period of 7.6 years and is at perihelion at 1.9 au in June, 0.12
days later than predicted from the discovery apparition. [MPEC 2013-B18, 2013 January 18]
2013 AL76 (P/Catalina)
A 20th magnitude asteroid discovered by the Catalina Sky Survey on January 14.21, was found to
be cometary during follow-up
observations by professional and amateur astrometrists, including Peter Birtwhistle, Gary Hug and
Hidetaka Sato.
The comet was at perihelion at 2.0 au in 2012 December and has a period of around 16
years. [MPEC 2013-B77, 2013 January 23]
A/2013 AZ60 (Lemmon)
This 19th magnitude object was discovered by the Mt Lemmon Survey on January 10.25
It is classed as a Centaur, but orbital studies suggest that it may be a "Super-comet".
The object was at perihelion at 7.9 au in 2014 November and has a period of around 30,000 years
with aphelion at nearly 2000 au. It has a diameter of around 60km, a rotation period of about
9.4 hours and an albedo of only 2.9% making it the darkest body amongst the known TNOs. The orbit
is unstable and it may be ejected from the solar system within 700,000 years. For more information
see http://arxiv.org/abs/1507.05468
A/2013 AS105 [ESAOGS]
This unusual asteroid was discovered by the ESA Optical Ground Station at Tenerife with the 1.0m
reflector on January 15.07. The initial orbit gave a period of around 160
years with perihelion at
5.4 au in 2011 May. [MPEC 2013-B21, 2013 January 18, 11-day orbit].
Aphelion was at around 55 au.
In this orbit it could approach to within 0.5 au of Jupiter. The Tisserand parameter
of the orbit with respect to Jupiter was 2.84. Such an orbit is typical of a potential Jupiter family comet.

The object was subsequently linked to 2010 AO137 with other observations back to
2007. The more definitive orbit is less interesting, with no Jupiter encounters, and
a period of 65 years. Tj is 2.93. [MPEC 2013-B21, 2013 January 19]

2013 B1 (278P/McNaught)
Jim Scotti recovered 2006 K2 in Spacewatch II images taken with the 1.8-m f/2.7 reflector
at Kitt Peak on January 19.53. It has a period of 7.1 years and is at perihelion at 2.1 au in August, 0.17
days earlier than predicted from the discovery apparition. [MPEC 2013-B58, 2013 January 21]
2013 B2 (Catalina)
The Catalina Sky Survey discovered a 19th magnitude comet on January 16.23. [MPEC 2013-B84, 2013 January 23]
It is at perihelion in July at 3.7 au.
A/2013 BN27 [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m
Schmidt on January 17.33. [MPEC 2013-B64, 2013 January 21, 4-day orbit]. The retrograde orbit has a period of around 500
years with perihelion at
1.6 au in 2012 October.
Aphelion is at around 125 au.
The Tisserand parameter of the orbit with respect to Jupiter is -0.23.
A/2013 BL76 (Lemmon)
Elements for a 21st magnitude object discovered by the Mt Lemmon Survey on January 20.08
were listed amongst those of comets. [MPEC 2013-C12, 2013 February 3] It is now classed as a Trans-Neptunian Object (TNO).
The object was at perihelion at 8.4 au in 2012 October and has a slightly retrograde orbit
with a period of over 40,000 years.
2013 C1 (280P/Larsen)
Jim Scotti recovered 2004 H2 in Spacewatch II images taken with the 1.8-m f/2.7 reflector
at Kitt Peak on February 5.50. It has a period of 9.6 years and was at perihelion at 2.6 au in December, 0.58
days earlier than predicted from the discovery apparition. [MPEC 2013-C25, 2013 February 6]
2013 C2 (Tenagra)
Michael Schwartz and Paulo Holvorcem discovered a very distant comet on 2013 February 14.24 at the Tenagra II Observatory
in Arizona. At discovery the comet was around 19th magnitude and over 9 au from the
Earth. [MPEC 2013-D22, 2013 February 17] Perihelion is at 9.1 au in 2015
August. It has a period of around 60 years. Given the distant orbit, little change
in the brightness of the comet was expected, and from 2013 March to 2015 January Kevin
Hills reported it at around 18th magnitude. It seems to have brightened
significantly during 2015 February from 17th magnitude at the beginning of the month to
15th magnitude on the 23rd. Then on 2015 February 27 it was reported at 14th
magnitude by Marco Goiato in a visual observation with his 0.22m reflector.
2013 CE31 (281P/MOSS)
Claudine Rinner at the Morocco Oukaimeden Sky Survey (MOSS) discovered an object on February 5.11,
that was initially flagged as an asteroid. Pre-discovery images were found in Spacewatch data from January.
Cometary features were found.
It reached perihelion at 4.0 au in 2012 May and has a period of around 11 years.

With further astrometry leading to an improved orbit, Maik Meyer found and measured the
comet in NEAT images from February and March 2002, and the comet was also found in
Spacewatch images from 2000 November. The comet made an approach to 0.4 au of Jupiter in
1999 which reduced the perihelion distance from 4.6 au to its present value.

2013 CU129 (P/Pan-STARRS)
An asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on February 13.32. Subsequent observations in 2013 June showed
cometary features. [MPEC 2013-L64, 2013 June 13].
The comet has a period of 4.9 years with perihelion at 0.80 au in 2013 August.
It makes relatively frequent approaches to both Jupiter and the Earth, with approaches
to our planet in 2018 (0.45 au) and 2023 (0.12 au).

A/2013 CY133 [Pan-STARRS]
This Centaur asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on February 14.40. [MPEC 2013-D25, 2013 February 18, 4-day orbit].
The asteroid has a period of around 22 years with perihelion at
5.8 au in 2014 December.
Aphelion was at around 10 au.
The Tisserand parameter of the orbit with respect to Jupiter was 2.92.
2013 D1 (Holvorcem)
Paulo Holvorcem discovered a comet on 2013 February 16.31 with the 0.41m astrograph at the Tenagra II Observatory
in Arizona. At discovery the comet was around 19th magnitude. [MPEC 2013-D41, 2013 February 20]
It has perihelion at 2.5 au in 2013 April. It has a period of around 40 years.
2013 E1 (McNaught)
Rob McNaught discovered a 19th magnitude comet on March 4.74 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet reached perihelion at 7.8 au in 2013 June. The latest orbit is strongly
hyperbolic.
2013 E2 (Iwamoto)
Masayuki Iwamoto discovered a 14th magnitude comet on images taken with his 10cm refractor at Tokushima on March 10.83.
The comet was near perihelion at 1.4 au and was just over 40 degrees elongation from the Sun in the dawn sky.
Calculations by Hirohisa Sato show that the comet is in a long period orbit. Marco Antônio Coelho Goiato
estimated the comet at about 11.0 in his 0.22-m reflector on March 23.35.

2013 EV9 (283P/Spacewatch)
A 19th magnitude asteroid was discovered by Spacewatch on March 2.28 with the 0.9m reflector.
Cometary characteristics were noted in images taken by Hidetaka Sato in 2013 April using
the remote 0.51m telescope at the iTelescope Observatory at Siding Spring, and confirmed
by other observers, and earlier observations were found from 2013 February. The comet was at perihelion at
2.1 au in 2013 April and has a period of around 8 years. [MPEC 2013-J07, 2013 May 2]
This was another confirmation of cometary features by the T3 project. Andrew Lowe quickly reported that he found astrometry from 1996 and 2005 and that the comet had
made a number of approaches to within 0.5 au of Jupiter between 1600 and 2400.
2013 EW90 (P/Tenagra)
Michael Schwartz and Paulo Holvorcem discovered an asteroid like object of 19th magnitude on 2013 March 3.19
at the Tenagra II Observatory
in Arizona. Later observations then showed cometary features. [MPEC 2013-J52, 2013 May 13]
Perihelion was at 3.3 au in 2012
October. It has a period of around 8 years.
2013 F1 (Boattini)
Andrea Boattini discovered an 18th magnitude comet on March 23.34 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. The comet was at perihelion at 1.9 au in 2012 December.
2013 F2 (Catalina)
An 18th magnitude comet was discovered on March 24.18 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. Pre-discovery images from 2012 December, 2013 January, and March were found
in Pan-STARRS data. The comet was at perihelion at 6.2 au in 2013 April.
2013 F3 (McNaught)
Rob McNaught discovered a 17th magnitude comet on March 29.76 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet reached perihelion at 2.3 au in 2013 May. It has a period of around 80
years.
2013 G1 (P/Kowalski)
Richard Kowalski discovered an 18th magnitude comet on April 2.43 on images taken during the Mt Lemmon Survey with
the 1.5m reflector. This was the 150th comet discovered by the Catalina
/Mt Lemmon Sky Survey. The orbital inclination is low, and an orbit computation by
Hirohisa Sato suggests an elliptical orbit with a period of 17 years and perihelion at 3.4
au in 2013 November is fitted by the astrometry. The latest orbit has a period of 18 years and perihelion at
3.3
au in 2013 December. The comet made an approach to Jupiter in 1927, and then had a very close approach to within 0.003 au of Saturn in 2001 April.
This encounter increased the perihelion distance from around 2 au to its present 3.3 au.
2013 G2 (McNaught)
Rob McNaught discovered a 17th magnitude comet on April 8.72 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet was at perihelion at 2.2 au in 2012 December. This was Rob McNaught's 75th discovery.
2013 G3 (PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on April 10.42. The discovery MPEC reported
that it reaches perihelion at 4.3 au in 2015 January and
has a period of 33.2 years.
The MPEC orbit was based on only a four day arc and seemed unduly precise for this limited amount of data. As a contrast the JPL
orbit viewed on April 16 was hyperbolic! This indicates that not too much credence should be given to preliminary orbits - they
are an aid to predicting the position over the next few days, but not much more. The
latest orbit [MPEC 2013-K38, 2013 May 24] gives perihelion at 3.9 au in 2014 November.
2013 G4 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on April 12.49. It was at perihelion at 2.6 au in 2013
February and
has a period of around 9 years.
2013 G5 (Catalina)
An 18th magnitude comet was discovered on April 13.46 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. The comet was at perihelion at 0.9 au in 2013 September.
JPL give a MOID of 0.07 au, so a meteor shower is a possibility.
2013 G6 (Lemmon)
A 19th magnitude comet was discovered on April 13.48 on images taken during the Mt Lemmon Survey with
the 1.5m reflector. It was at perihelion in 2013 July at 2.0 au.
2013 G7 (McNaught)
Rob McNaught discovered an 18th magnitude comet on April 13.65 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
The comet will reach perihelion at 4.7 au in 2014 March.
2013 G8 (PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on April 14.60. [MPEC 2013-H22, 2013 April 19]. It reaches perihelion at
5.1 au in 2013 November.
2013 G9 (Tenagra)
Michael Schwartz and Paulo Holvorcem discovered a distant comet on 2013 April 15.39 at the Tenagra II Observatory
in Arizona. At discovery the comet was around 20th magnitude and over 6 au from the
Earth. [MPEC 2013-H23, 2013 April 19] Perihelion is at 5.3 au in 2015
January.
A/2013 GY54 [Pan-STARRS]
This unusual asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on April 4.38. The asteroid has a period of around 50 years with perihelion at
4.6 au in 2014 October. [MPEC 2013-G47, 2013 April, 34-day orbit].
Aphelion is at around 22 au. The Tisserand parameter of the orbit with respect to Jupiter was
2.78.
2013 H1 (La Sagra)
The La Sagra team at the OAM Observatory discovered an 18th magnitude comet on April 19.11 with the 0.45m reflector.
The comet was at perihelion at 2.6 au in 2013 May. [MPEC 2013-H27, 2013 April 22]
2013 H2 (Boattini)
Andrea Boattini discovered an 18th magnitude comet on April 22.45 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-H45, 2013 April 25] The preliminary MPEC orbit
suggested that the
comet was at perihelion at 2.5 au in 2011 March and had a period of 36.5 years. This was based on a three day arc.
Not surprisingly the latest orbit gives something completely different - a hyperbolic
orbit with perihelion at 7.5 au in 2014 January.
A/2013 HA [Mt Lemmon]
This unusual asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on April 16.24. The orbit has a period of around 10
years with perihelion at
1.7 au in 2013 May. [MPEC 2013-H14, 2013 April 17, 3-month orbit].
The Tisserand parameter of the orbit with respect to Jupiter is 2.55 and the object can approach within 0.5 au of the planet.
It can also approach within 0.1 au of Mars, and will do so in 2098. It is an outer Main Belt Asteroid.
A/2013 HS150 [Cerro Tololo]
This Centaur asteroid was discovered with the Cerro Tololo Dark Energy Camera on the 4.0m
CTIO reflector on April 16.30. [MPEC 2013-Q30, 2013 August 25, 3-day orbit].
The asteroid has a retrograde orbit with a period of around 130 years and perihelion at
2.8 au in 2013 January.
Aphelion is at around 50 au. The Tisserand parameter of the orbit with respect to Jupiter was
-0.03.
2013 J1 (284P/McNaught)
Jim Scotti recovered 2007 H1 with the Spacewatch 1.8m reflector on May 1.41. The comet will return 0.22 days earlier than
predicted.
2013 J2 (P/McNaught)
Rob McNaught discovered an 18th magnitude comet on May 8.75 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
[MPEC 2013-J38, 2013 May 10]. The comet reached perihelion at 2.1 au in 2013
August. Although the discovery MPEC gave a periodic orbit of about nine years (based
on an arc of 1.7 days) subsequent circulars gave a parabolic orbit whilst retaining the P/
designation. This was a good move, as the latest orbit gives a period of around 16
years.

2013 J3 (McNaught)
Rob McNaught discovered a 17th magnitude comet on May 8.55 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
[MPEC 2013-J40, 2013 May 11] The comet was at perihelion at 4.0 au in 2013
February.
2013 J4 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on May 5.26. It will reach perihelion at 2.3 au in 2013
July and
has a period of around 16 years. [MPEC 2013-J51, 2013 May 13]. There are only observations over
a seven day arc.
2013 J5 (Boattini)
Andrea Boattini discovered a 20th magnitude comet on May 13.32 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-K25, 2013 May 20] The comet was at perihelion at 4.9 au in 2012 December.
2013 J6 (Catalina)
An 18th magnitude comet was discovered on May 9.37 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-K31, 2013 May 21] The comet was at perihelion at 2.4 au in 2013 April.
A/2013 JD4 [Mt Lemmon]
This Centaur asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on May 3.32. [MPEC 2013-J19, 2013 May 5, 2-day orbit].
The orbit has a high inclination with a period of around 40
years and perihelion at 1.6 au in 2013 January.
The Tisserand parameter of the orbit with respect to Jupiter is 0.88 and the object can approach within 0.4 au of the planet.
2013 K1 (Christensen)
Eric Christensen discovered a 17th magnitude comet on May 18.46 on images taken during the Mt Lemmon Survey with
the 1.5m reflector. [MPEC 2013-K26, 2013 May 20].
The comet was near perihelion at 0.9 au, but is intrinsically faint and 0.8 au from the Earth.
This is the 50th comet discovered from Mt Lemmon.

Cedric Bemer notes that the orbit has an Earth MOID of 0.06 au, so a meteor shower is possible with the Earth reaching this
point 54 days after the comet. He suggests looking around 05:30 UT on 2013 July 29.

2013 K2 (285P/LINEAR)
Hidetaka Sato recovered 2003 U2 with the remote iTelescope 0.51m astrograph at Mayhill Observatory on May 8.45. Perihelion
is 0.18 days earlier than predicted. [MPEC 2013-K37, 2013 May 24]
2013 K3 (286P/Christensen)
Hidetaka Sato recovered 2005 L4 with the remote iTelescope 0.51m astrograph at Siding Spring on May 19.70. Perihelion
is 0.18 days earlier than predicted. [MPEC 2013-K47, 2013 May 31]
2013 L1 (287P/Christensen)
Jim Scotti recovered 2006 R2 with the Spacewatch 1.8m reflector on June 1.29. The comet will return 0.75 days earlier than
predicted.
2013 L2 (Catalina)
A 19th magnitude comet was discovered on June 2.30 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-L41, 2013 June 9] The comet was at perihelion at
4.9 au in 2012 May.
A/2013 LA2 [Pan-STARRS]
This Centaur asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on June 1.37. [MPEC 2013-L23, 2013 June 5, 4-day orbit].
The asteroid has a retrograde orbit with a period of around 20 years and perihelion at
3.0 au in 2013 January.
Aphelion is at around 12 au. The Tisserand parameter of the orbit with respect to Jupiter was
-1.23. The object can approach Jupiter within 0.5 au and Saturn within 1 au.
A/2013 LD16 [Mt Lemmon]
This Trans-Neptunian asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on June 6.28. [MPEC 2013-L47, 2013 June 10, 4-day orbit].
The orbit is retrograde with a period of around 600 years and perihelion at
2.5 au in 2013 October.
The Tisserand parameter of the orbit with respect to Jupiter is -1.70.
A/2013 LH16 [Pan-STARRS]
This unusual asteroid, classified as an Apollo, was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on June 7.47. [MPEC 2013-L51, 2013 June 10, 3-day orbit].
The asteroid has a period of around 5 years with perihelion at 0.7 au in 2013 September.
The Tisserand parameter of the orbit with respect to Jupiter was
2.68.
A/2013 LU28 = 2014 LJ9 = 2015 KB157 [Mt Lemmon]
This Trans-Neptunian asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on 2013 June 8.38. [MPEC 2013-L69, 2013 June 15]. Subsequently it was given
other designations, which Gareth Williams linked to the primary discovery.
The orbit is retrograde with a period of over 2000 years and perihelion at
8.7 au in 2024.
The Tisserand parameter of the orbit with respect to Jupiter is -2.07.
A/2013 LG29 [Pan-STARRS]
This Centaur asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on June 12.37. [MPEC 2013-M02, 2013 June 16, 4-day orbit].
The asteroid has a period of around 70 years with perihelion at 3.6 au in 2013 August.
The Tisserand parameter of the orbit with respect to Jupiter was
2.44. The object can approach within 1 au of Saturn and 1.2 au of Uranus.
2013 N1 (290P/Jager)
K Sarneczky and G Marschalko recovered 1998 U3 with the 0.6m Schmidt at Konkoly Observatory on July 8.04.
Perihelion is 1.96 days earlier than predicted. [MPEC 2013-N46, 2013 July 13]
2013 N2 (291P/NEAT)
Gary Hug recovered 2003 S1 with the 0.56m reflector at Sandlot Observatory, Scranton, on July 11.39.
Perihelion is 0.67 days earlier than predicted. [MPEC 2013-N48, 2013 July 13]
2013 N3 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on July 4.44. [MPEC 2013-N50, 2013 July 13]
It will reach perihelion at 3.0 au in 2014
February and has a period of around 20 years.
2013 N4 (Borisov)
Gennady Borisov discovered a 17th magnitude comet with a 0.2m astrograph, 0.25m reflector and 0.32m reflector
at the Crimea-Nauchnij observatory in collaboration with I Ionov, O Bryzgalov and Ayrtom Novichonok on July 8.99.
[MPEC 2013-N51, 2013 July 13]
The comet perhaps reached 9th magnitude at perihelion, however it was at a small solar
elongation. It was at perihelion at 1.2 au in 2013 August and has a period of around 90
years, so might have been seen previously at a favourable return. The elongation,
although still poor, is increasing and Seichi Yoshida observed the comet at 11th magnitude
in early October.

2013 N5 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on July 14.58. [MPEC 2013-P17, 2013 August 4]
It was at perihelion at 1.8 au in 2013
July and has a period of around 18 years.

The comet is one of those suspected to have undergone nuclear splitting according to
the list of Marcos & Marcos [Dynamically correlated minor bodies in the outer
solar system, MNRAS, 474, 838, 2018 February]. They link it to 285P/LINEAR.

A/2013 NS11 [Pan-STARRS]
This Centaur asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on July 5.27. [MPEC 2013-N43, 2013 July 12, 7-day orbit].
The asteroid has a retrograde orbit with a period of around 45 years and perihelion at
2.7 au in 2014 September.
The Tisserand parameter of the orbit with respect to Jupiter is
-0.83.
A/2013 NF15 [Pan-STARRS]
This unusual asteroid was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on July 14.49. [MPEC 2013-O06, 2013 July 16, 1-day orbit].
The asteroid has an orbit with a period of around 11 years and perihelion at
1.4 au in 2013 June.
The Tisserand parameter of the orbit with respect to Jupiter is
2.38 and it can approach within 0.2 au of the planet.
A/2013 NZ23 [Pan-STARRS]
This potentially hazardous asteroid, classified as an Amor, was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on July 14.58. [MPEC 2013-O41, 2013 July 27, 1-day orbit]. The asteroid has an orbit with a
period of around 5.7 years and perihelion at
1.0 au in 2013 July. The Earth MOID is 0.02 au.
The Tisserand parameter of the orbit with respect to Jupiter is
2.74 and it can approach within 0.1 au of the planet.
2013 O1 (292P/Li)
Hidetaka Sato imaged comet 1998 Y2 (P/Li) on May 9.80 with the 0.51m astrograph of the iTelescope at Siding Spring,
but confirmation of the recovery was not made until July 16.39 when it was imaged by M Masek
with the 0.3m reflector at the Pierre Auger Observatory, Malargue. [MPEC 2013-O52, 2013 July 27]
Perihelion is 0.85 days later than predicted.
2013 O2 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on July 16.60 [MPEC 2013-O53, 2013 July 27]
It will reach perihelion at 2.1 au in 2013
December and has a period of around 7.5 years. It makes occasional approaches to Jupiter,
most recently to within 0.3 au in 1994. This reduced the perihelion distance from 2.6 au to
its present value.
2013 O3 (McNaught)
Rob McNaught discovered an 18th magnitude comet on July 24.65 during the Siding Spring Survey with the 0.5m Uppsala Schmidt.
[MPEC 2013-O54, 2013 July 27] The comet reached perihelion at 3.2 au in 2013
September.
A/2013 OP3 [Pan-STARRS]
This unusual asteroid, classified as an Amor, was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on July 16.52. The asteroid has an orbit with a
period of around 8 years and perihelion at
1.2 au in 2013 September. The Earth MOID is 0.2 au. [MPEC 2013-O45, 2013 July 27, 0.8-day orbit].
The Tisserand parameter of the orbit with respect to Jupiter is
2.57 and it can approach within 0.3 au of the planet.
A/2013 OP5 [Siding Spring]
This unusual asteroid was discovered during the Siding Spring Survey with the 0.5-m
Uppsala Schmidt on July 29.67. The asteroid has an orbit with a
period of around 5.8 years and perihelion at
1.3 au in 2013 August. [MPEC 2013-P06, 2013 August 1, 3-day orbit].
The Tisserand parameter of the orbit with respect to Jupiter is
2.87 and it can approach within 0.3 au of the planet.
2013 P1 (P/PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on August 1.54. [MPEC 2013-P18, 2013 August 4]
It was at perihelion at 3.4 au in 2013 February and has a period of around 25 years. There
were pre-discovery images from Spacewatch taken on July 28.28.
2013 P2 (PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on August 4.37,
with prediscovery images from July 26.52. [MPEC 2013-P42, 2013 August 7]
It will reach perihelion at 2.8 au in 2014 February.
2013 P3 (Palomar)
The Palomar Transient Factory discovered a 19th magnitude comet on August 8.37 with the 1.2m Schmidt.
[MPEC 2013-Q02, 2013 August 16]. It will be at perihelion at 8.6 in 2014 November.
2013 P4 (PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on August 15.49.
[MPEC 2013-Q34, 2013 August 26]
It will reach perihelion at 6.0 au in 2014 August and has a period of around 60 years.
2013 P5 (311P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on August 15.50. [MPEC 2013-Q37, 2013 August 27]
It will reach perihelion at 1.9 au in 2014 April and has a low eccentricity and a very short period of around 3.2 years.
There are some similarities between its orbit and that of Flora group asteroids and it is probably another example of
a Main Belt Comet. The HST took images of it on September 10 and 23,
showing a complex tail structure that might be linked to rotation rate. It was
numbered in 2014 once observations extended over a complete orbit.
2013 PE67 (Catalina-Spacewatch)
This comet, originally designated as a Trans-Neptunian asteroid was discovered by the Catalina Sky Survey
with the 0.68m Schmidt on August 9.27. [MPEC 2013-Q15, 2013 August 18, 15-day orbit].
The retrograde orbit has a period of around 400 years with perihelion at
1.8 au in 2013 December. Aphelion is at over 100 au.
The Tisserand parameter of the orbit with respect to Jupiter is -0.66. The orbit
is cometary, so this may be a "dead" comet and could show activity when it gets closer
to perihelion.

My suggestion was followed up by
Hidetaka Sato, who reported a diffuse appearance in images taken
on 2014 March 9.2, with further reports from other observers following in the next few days.
It took until April before a CBET announcing the new designation was released [CBET 3851, 2014 April 10]
and this included Spacewatch as co-discoverers as they had taken images just a few hours after
Catalina.

A/2013 QH10 [Pan-STARRS]
This unusual asteroid, classified as an Amor, was discovered by Pan-STARRS 1 with the 1.8m
R-C telescope on August 24.45. [MPEC 2013-Q38, 2013 August 28, 4-day orbit].
The asteroid has an orbit with a period of around 5.2 years and perihelion at
1.2 au in 2013 April. The Earth MOID is 0.2 au.
The Tisserand parameter of the orbit with respect to Jupiter is
2.93 and it can approach within 0.4 au of the planet, the most recent close approach
being in 1953.
2013 R1 (Lovejoy)
Terry Lovejoy discovered a 14th magnitude comet on September 7.69 with his 0.20-m Schmidt-Cassegrain
and CCD camera. [MPEC 2013-R72, 2013 September 9]. Terry has provided an
account of the discovery. The comet had perihelion at
0.8 au near the December Solstice. The comet approached the Earth to 0.4 au on November 20 and
was an easy binocular object, with a few naked eye observations around this time. Observations
dropped when it was lost to view from the evening sky in early January. It was conveniently placed from my bedroom
window in late winter, so I made a few early morning
observations which showed it fading quite rapidly. It had a short tail, which
imagers showed to be in constant evolution.

233 visual observations received so far suggest a
change in photometric behaviour around the time of perihelion, with the comet fading as m =
6.5 + 5 log d + 10.9 log r.

2013 R2 (293P/Spacewatch)
Jim Scotti recovered 2006 XG16 with the 1.8-m Spacewatch II reflector on September 14.48 when it was
22nd magnitude. [MPEC 2013-S01, 2013 September 16] The comet's orbit approaches within 0.18 au of the Earth.
2013 R3 (P/Catalina-PanSTARRS)
The Catalina Sky Survey discovered a 19th magnitude comet on September 15.38 and it was
independently found by Pan-STARRS on September 15.54. [MPEC 2013-S53, 2013 September 27]
It was at perihelion at 2.2 au in 2013 August and has a period of around 5.3 years.

The comet is one of those known to have undergone nuclear splitting
according to the list of Marcos & Marcos [Dynamically correlated minor
bodies in the outer solar system, MNRAS, 474, 838, 2018 February] It is a
Main Belt Comet.
2013 S1 (Catalina)
A 19th magnitude comet was discovered on September 28.39 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-T27, 2013 October 4] The comet was at perihelion at about 2.8 au in 2013 August.
2013 T1 (P/PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on October 5.37. [MPEC 2013-T76, 2013 October 8]
It was at perihelion at 2.2 au in 2013 July and has a period of around 14 years. There
were pre-discovery images from Mt Lemmon taken on September 13.4.
2013 T2 (P/Schwartz)
Michael Schwartz discovered a 19th magnitude comet in images taken with the Tenagra II 0.41-m f3.75
astrograph on October 15.36. Prediscovery images were found in Catalina Sky Survey data from September
14. [MPEC 2013-U18, 2013 October 22] The comet has a period of around 6.3 years with perihelion at
1.6 au in 2013 June. It will fade.
2013 TW5 (Spacewatch)
Tim Bressi discovered this object at the Steward Observatory, Kitt Peak with the 0.9m
Spacewatch reflector on October 3.49. It was first reported as an unusual asteroid, which had a period of around 16 years with perihelion at
3.1 AU in 2015 September. [MPEC 2013-T47, 2013 October 6, 3-day orbit]. Six days later a further MPEC [2013-T92, 2013 October 12] reported the object to be a comet, following further
observations by Spacewatch and
Hidetaka Sato. The MPEC stated "Very preliminary elements" yet still gave them to five or more
places of decimals. Later circulars give a long period orbit with perihelion at 5.8 au in 2014
August.
2013 TL117 (P/Lemmon)
An unusual asteroid, classified as an Amor, was discovered during the Mt Lemmon survey with the 1.5m
telescope on October 4.25 and was also designated as 2013 UT2. [MPEC 2013-U68, 2013 October 28, 24-day orbit].
Further observations showed cometary characteristics, and the object was given a cometary designation on MPEC 2013-X59
[2013 December 12]. The object has a period of around 6.8 years and perihelion at
1.1 au in 2014 February.
The Tisserand parameter of the orbit with respect to Jupiter is 2.64 and the object can approach within 0.5 au of the planet
and to 0.2 au from the Earth, which it did in 1980.
A/2013 TT4 [Mt Lemmon]
This unusual asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on October 3.40. [MPEC 2013-T36, 2013 October 4, 1-day orbit].
The object has a period of around 12 years and perihelion at
1.4 au in 2013 August. No further observations have been reported.
The Tisserand parameter of the orbit with respect to Jupiter is 2.36 and the object can approach within 0.3 au of the planet.
2013 U1 (Catalina)
An 18th magnitude comet was discovered on October 22.11 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-U83, 2013 October 30] The comet was near perihelion at about 2.4 au and
has a period of around 40 years.
2013 U2 (Holvorcem)
Brazilian amateur Paulo Holvorcem disovered a 19th magnitude comet on October 23.42 with the 0.41-m f3.75 astrograph at
the Tenagra II Observatory. [MPEC 2013-U84, 2013 October 30] The comet will reach perihelion at about
5.1 au
in 2014 October.
2013 UQ4 (Catalina)
This very unusual asteroid, originally classified as an Amor, was discovered by the Catalina Sky Survey with the 0.68m
Schmidt on October 23.37. [MPEC 2013-U54, 2013 October 27, 3-day orbit].
The asteroid has a retrograde orbit with a period of over 400 years and perihelion at
1.1 au in 2014 July. The Earth MOID is 0.11 au.
The Tisserand parameter of the orbit with respect to Jupiter is
-0.97. It will approach the Earth within 0.3 au in 2014 July.

On 2014 May 7 Ayrtom Novichonok and T Prystavski noted cometary features in images taken
with the 0.5m iTelescope at Siding Spring. An MPEC giving the cometary designation [MPEC 2014-K36]
was finally issued on May 23.

It is well placed in northern
skies at perihelion and could reach 10th magnitude.

2013 US10 (Catalina)
Not surprisingly, a 19th magnitude object discovered during the course of the Catalina Sky Survey
with the 0.68-m Schmidt on October 31.16 [MPEC 2013-V05, 2013 November 2] has turned out to be a comet.
The asteroidal orbit seemed very odd, with period of 6.1 years and perihelion at 0.4 au, although it made
no nearby passes to Jupiter, and the asteroid had a fairly bright absolute magnitude. The orbit had a MOID with respect
to Earth of 0.54 au. The cometary orbit [MPEC 2013-V31, 2013 November 6, 3-months observations] gives
perihelion at about 0.8 au
in 2015 November, a scenario suggested by Reinder Bouma soon after the asteroidal orbit was published. The comet
was very distant from the Sun, being 8.3 au away at discovery and still 3.9 au away
in mid December 2014. It was slightly fainter than expected when it was observed
visually after solar conjunction in 2015 April and the rate of brightening seemed to be
slowing, however there has been no significant change with additional observations in June, which put
the comet at around 10.5. It was 9th magnitude by July and had reached 6.5 by
the end of August. It was picked up after perihelion by Juan Jose Gonzalez on November 22 at 6th magnitude.
I estimated it at 6.3 in 20x80B on December 4 from central Cambridge and a similar
brightness at the end of the month. By early February the comet was
fading rapidly and becoming a difficult object, although well placed at high northern
declination..

A/2013 UR3 [Catalina]
This unusual asteroid, classified as an Amor, was discovered by the Catalina Sky Survey with the 0.68m
Schmidt on October 23.30. [MPEC 2013-U45, 2013 October 26]. The asteroid has an orbit with a
period of 5.7 years and perihelion at
1.3 au in 2013 December. The Earth MOID is 0.3 au.
The Tisserand parameter of the orbit with respect to Jupiter is 2.77 and it can approach within
0.5 au of the planet.
2013 V1 (Boattini)
Andrea Boattini discovered an 16th magnitude comet on November 4.38 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-V32, 2013 November 6]. The comet will reach perihelion at
1.7 au in 2014 April,
when it may be 14th magnitude.

2013 V2 (Borisov)
Gennady Borisov discovered a 17th magnitude comet with the 0.2m astrograph
at the Crimea-Nauchnij observatory on November 6.01. [MPEC 2013-V43, 2013 November 8]
The comet will reach perihelion at 3.5 au in 2014 October. Visual reports suggest
that it may be as bright as 11th magnitude.
2013 V3 (Nevski)
Vitali Nevski discovered a 15th magnitude comet with
the 0.2-m f/3 reflector of the International Scientific Optical Network (ISON)
at Kislovodsk Observatory, Russia on November 6.99. [MPEC 2013-V45, 2013 November 8]
The comet was just past perihelion at 1.4 au and near its brightest. It has a period
of around 45 years.

2013 V4 (Catalina)
An 18th magnitude comet was discovered on November 9.28 during the course of the Catalina Sky Survey
with the 0.68-m Schmidt. [MPEC 2013-V94, 2013 November 15] The comet will reach perihelion at 5.2 au in
2015 October.
2013 V5 (Oukaimeden)
An 18th magnitude comet was discovered on November 12.15 by Michel Ory using the 0.5-m
reflector at the Oukaimeden Observatory, Marrakech. [MPEC 2013-V95, 2013 November 15]
The comet reached perihelion at 0.6 au in 2014 September when it was best seen from the Southern Hemisphere.
It appears to have peaked at around magnitude 6.5 near perihelion and is now fading quite
quickly. It has very low activity.

2013 V6 (315P/LONEOS)
A possible recovery of 2004 VR8 (P/LONEOS) with the 3.5m Apache Point reflector on 2013 November 6.15 was confirmed
with the same telescope on 2014 December 8.09. The indicated correction to the prediction by G. V. Willliams on MPC 84327
is Delta(T) = -0.71 day. [CBET 4038, MPEC 2014-Y45, 2014 December 24]
A/2013 VF2 = 2011 OD39 = 2010 HS10 []
This unusual asteroid, classified as a Jupiter Trojan, has an orbit with a
period of 12.0 years and perihelion at
5.0 au in 2008 October. [MPEC 2013-V44, 2013 November 8].
The Tisserand parameter of the orbit with respect to Jupiter is
2.96 and it can approach within 0.2 au of the planet.
The orbit shows some similarity to that of 29P/Schwassmann-Wachmann.
A/2013 VX9 [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m
Schmidt on November 4.38. [MPEC 2013-V50, 2013 November 9, 5-day orbit].
The asteroid has an orbit with a period of around 10 years and perihelion at
2.0 au in 2013 October. It is classed as an Outer Main Belt Asteroid.
The Tisserand parameter of the orbit with respect to Jupiter is
2.40 and it can approach within 0.5 au of the planet.
2013 W1 (P/PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on November 24.31. [MPEC 2013-W23, 2013 November 27]
It will reach perihelion at 1.4 au in 2014 March and has a period of around 6.5 years. There
were pre-discovery images from the Catalina Sky Survey taken on November 9.3.
2013 W2 (PanSTARRS)
Pan-STARRS discovered a 21st magnitude comet on November 27.37.
[MPEC 2013-X26, 2013 December 5]
It will reach perihelion at 4.5 au in 2015 January and has a period of
around 30 years.
2013 X1 (PanSTARRS)
Pan-STARRS discovered a 20th magnitude comet on December 4.43. There
were pre-discovery images from the Mt Lemmon Survey taken on November 29.5. [MPEC 2013-X29, 2013 December 6]
It will reach perihelion at 1.3 au in 2016 April according to the discovery elements,
however as these were based on an arc of 6 days with the comet over 8 au from the Earth
they seemed likely to change, despite being given to a precision of five decimal places.
Rather more realistically the JPL Horizons small-body browser gave the 1-sigma
uncertainty in q as 2.2 au, and in the perihelion date as 365 days. Surprisingly,
further orbits continued to give similar elements and steadily reduced the uncertainty. The
comet brightened quite rapidly in 2016 January and became visible in large binoculars. The
rapid brightening generated many reports of an outburst, but these were premature as
there was no substantial deviation away from the mean light curve at that time. At other times
there were as many observations below the mean curve, yet there were few reports that it
was disintegrating.

It was recovered after solar conjunction by Marco Goiato on April 17.35 in
20x100B. It was fainter than originally expected at 7.5, but was moderately condensed.
It reached a peak of around 6.5 in June, but is now fading rapidly. It is visible from the Southern Hemisphere.

94 visual
and electronic equivalent observations received so far suggest a preliminary light curve of m =
4.7±0.2 + 5 log d + 11.0±0.7 log r . The comet was significantly brighter than the
mean curve during 2016 January and February, which lends more credence to the idea of an
outburst, however the overall light-curve does not appear to show any discontinuity.

2013 X2 (294P/LINEAR)
Hidetaka Sato recovered 2008 A2 with the remote iTelescope 0.43m astrograph at Mayhill, New Mexico on December 11.51. Perihelion
is 0.24 days earlier than predicted. [MPEC 2013-X72, 2013 December 14]
2013 Y1 (295P/LINEAR)
Jim Scotti recovered 2002 AR2 with the 0.9m Spacewatch telescope at Kitt Peak on September 14.2, and it was also imaged by the Mount Lemmon
Survey during September and October, but it wasn't finally confirmed until Scotti imaged it with the 1.8-m Spacewatch II reflector on December 25.15 when it was
21st magnitude. [MPEC 2013-Y30, 2013 December 25] The comet returns to perihelion 0.7 days earlier than predicted.
2013 Y2 (PanSTARRS)
Pan-STARRS discovered an 18th magnitude comet on December 30.51.
Observations accumulated over the next ten
days before an orbit was published. [MPEC
2014-A59, 2014 January 10] It will reach
perihelion at 1.9 au in 2014 June.
2013 YG46 (P/Spacewatch)
A 20th magnitude object discovered by Spacewatch on December 27.27 was found to be cometary when observed in 2014 February.
[MPEC 2014-D12, 2014 February 20]. The comet was at perihelion at 1.8 au in 2011 January and has a period of around 6.1 years.
A/2013 YF48 [Mt Lemmon]
This unusual asteroid was discovered during the Mt Lemmon survey with the 1.5m
telescope on December 28.11. [MPEC 2013-Y73, 2013 December 31, 2-month orbit].
The object has a period of around 30 years and perihelion at
4.4 au in 2014 September. Aphelion is at around 14 au. It is classed as a Centaur asteroid.
The Tisserand parameter of the orbit with respect to Jupiter is 1.05
and the object can approach within 0.4 au of the planet.
A/2013 YG48 [Catalina]
This unusual asteroid was discovered by the Catalina Sky Survey with the 0.68m
Schmidt on December 28.36. [MPEC 2013-Y74, 2013 December 31, 3-day orbit].
The asteroid has an orbit with a period of around 25 years and perihelion at
2.0 au in 2014 March. Aphelion is at around 14 au. It is classed as a Centaur Asteroid.
The Tisserand parameter of the orbit with respect to Jupiter is
1.44. It can approach within 1.4 au of Saturn.
Ephemerides of current comets are available on the CBAT
ephemeris page and positions of newly discovered comets are on the
NEO confirmation page.
More information on LINEAR. A list of comets
discovered by selected search programs.
The Northumberland refractor
is the telescope that was used in the search for Neptune.
It now has a 0.30-m f20 doublet lens which gives a stellar limiting magnitude of around
15 at the zenith on good nights.
The Thorrowgood refractor was
built in 1864 and has a 0.20-m f14 doublet lens.
Published by Jonathan Shanklin. Jon Shanklin - jds@ast.cam.ac.uk